摘要
本文从分析Si在SiO_2上成核的一般过程出发,利用新的成核理论,分析出影响成核的重要因素是氢吸附;并着重针对ELO过程的特点,通过大量实验研究了各种条件对成核的影响,找到了既能完全抑制多晶成核又能实现侧向生长的最佳工艺条件.根据实验中测得的临界成核时间及沉积自由区宽度,采用间歇生长技术在20μm宽的SiO_2条上完全抑制了多晶成核,而加入 Br_2的生长/腐蚀循环工艺则在 30μm宽的SiO_2上完全抑制了多晶成核,为获得高质量的SOI材料打下了良好的基础.
According to the new nucleation theory,the important factor for polysilicon nucleationon SiO_2 surface is the adsorption of various substances on SiO_2 surface, especially the hydrogenadsorption. We have also studied the impacts of various experimental conditions for polysiliconnucleation in ELO processes, and found out the optimum growth condition for inhibition poly-silicon and realization lateral overgrowth simultaneously.According to critical nucleationtime and width of free deposition area obtained in experiments, the polysilicon nucleation on20μm wide SiO_2 strip has been suppressed by using intermittent growth technique; furthermore,the growth/Br_2 etching method make the surface of 30μm SiO_2 strip clean.All of these forma good foundation for getting high quality SOI structure material.
